sdvx: fix touchscreen and API touch in landscape mode (#859)

## Link to GitHub Issue or related Pull Request, if one exists
Fixes #858 

## Description of change
Landscape mode needs another adjustment applied to touch coordinates.

This fixex both native touch and wintouchemu paths.

## Testing
Tested landscape, also with full screen resolution changes.

src/spice2x/api/modules/touch.cpp

@@ -55,9 +55,10 @@ namespace api::modules {
         native_canvas_w = 0;
         native_canvas_h = 0;
         if (is_sdvx) {
-            // exceed gear subscreen, portrait after the rotation applied in apply_touch_errata
+            // landscape API coordinates already match the primary screen orientation;
-            native_canvas_w = 1080;
+            // portrait coordinates are rotated by apply_touch_errata
-            native_canvas_h = 1920;
+            native_canvas_w = GRAPHICS_FS_ORIENTATION_SWAP ? 1920 : 1080;
+            native_canvas_h = GRAPHICS_FS_ORIENTATION_SWAP ? 1080 : 1920;
         } else if (avs::game::is_model("LDJ")) {
             // TDJ subscreen; FHD models are upscaled to 1080p by apply_touch_errata
             native_canvas_w = is_tdj_fhd ? 1920 : 1280;
@@ -218,8 +219,8 @@ namespace api::modules {
             // the target of the touch events so just assume it's the sub screen
             x = x_raw * 1920 / 1280;
             y = y_raw * 1080 / 720;
-        } else if (is_sdvx) {
+        } else if (is_sdvx && !GRAPHICS_FS_ORIENTATION_SWAP) {
-            // for exceed gear, they are both 1080p screens, but need to apply transformation
+            // rotate API coordinates into SDVX's portrait touch space
             x = 1080 - y_raw;
             y = x_raw;
         }

src/spice2x/touch/native/transform.cpp

@@ -1,5 +1,6 @@
 #include "transform.h"
 
+#include "avs/game.h"
 #include "hooks/graphics/graphics.h"
 #include "overlay/overlay.h"
 #include "settings.h"
@@ -82,6 +83,25 @@ namespace nativetouch::transform {
         return overlay::OVERLAY->transform_touch_point(&position->x, &position->y);
     }
 
+    // the digitizer is mapped to the zero-based primary display, while SDVX
+    // still expects portrait coordinates when its image is rendered in landscape:
+    // (x, y) -> (width * (1 - y / height), height * x / width).
+    static bool transform_sdvx_landscape_touch_position(POINT *position) {
+        const auto landscape_width = static_cast<LONG>(GRAPHICS_FS_CUSTOM_RESOLUTION.has_value() ?
+            GRAPHICS_FS_CUSTOM_RESOLUTION.value().first : GRAPHICS_FS_ORIGINAL_HEIGHT);
+        const auto landscape_height = static_cast<LONG>(GRAPHICS_FS_CUSTOM_RESOLUTION.has_value() ?
+            GRAPHICS_FS_CUSTOM_RESOLUTION.value().second : GRAPHICS_FS_ORIGINAL_WIDTH);
+        if (landscape_width <= 0 || landscape_height <= 0) {
+            return false;
+        }
+
+        const auto input_x = position->x;
+        position->x = landscape_width -
+            MulDiv(position->y, landscape_width, landscape_height);
+        position->y = MulDiv(input_x, landscape_height, landscape_width);
+        return true;
+    }
+
     // convert physical screen coordinates to game touch coordinates for a known target
     bool screen_to_game(HWND window, POINT *position) {
         if (settings::SYNTHETIC_TOUCH_USES_CLIENT_COORDINATES) {
@@ -144,6 +164,13 @@ namespace nativetouch::transform {
         const auto dedicated_subscreen = is_tdj_dedicated_subscreen(TDJ_SUBSCREEN_WINDOW);
         const auto active_overlay = has_active_overlay_transform();
 
+        // special case for SDVX landscape mode
+        if (!dedicated_subscreen && !active_overlay &&
+            GRAPHICS_FS_ORIENTATION_SWAP && avs::game::is_model("KFC")) {
+            return transform_sdvx_landscape_touch_position(position) ?
+                Result::Transformed : Result::Rejected;
+        }
+
         // no dedicated subscreen or active overlay mapping; pass the point through unchanged
         if (!dedicated_subscreen && !active_overlay) {
             return Result::Unchanged;